Method for manufacturing metal sheets



5 sneetssheet 1V Filed. Aug. 10.,l 1957 hunt" 2.2!

/N VENTO/e CYL'. LEWELLEN, IMMO/v5 F. LEWELLEN,

ATTORNEYS AU@ 20, 1940- D. E. LEWELLEN x-:r AL '2,212,195

'ETHOD FUR MANUFACTURING METAL SHEETS 5 Sheets-Sheet 2 Filed Aug. 10, 1937 www A TTORNEYS A08. 20. 1940. D. E. LEwELLEN Er AL 2,212,195

METHOD FORMANUFACTURING METAL SHEETS Filed Aug. l0, 193'7l 3 Sheets-Sheet 3 INVENTOR EACY ELLEWELLEN, IMMONS FIEWELLEN,

ATTORNEYS Patented Aug. 20, 1940 param' ortica Martien non MANUFACTUMNG METAL snmrrs Darcy E. Lewellen and Emmons F. Lewcllen,

Columbus, Ind.

Application August 10,

i claim.

This invention relates to a method and apparatus for variable speed control of rollsv operating upon a sheet and similar mechanism.

Our invention relates to a method of handling sheets, preferably metal sheets, between rolls in order to increase the speed of handling the sheets and improve the nish thereof. Heretofore, the speed of handling a metal sheet as it is being rolled from heavier stock to thinner stock has been determined by that speed which would not pull the metal in two and rupture it when the machine was started. If the speed oi starting was so great that it did more than overcome the inertia of the mass so that the strength of the metal was exceeded, the metal would be rup tured. Therefore, it has been the practice even after starting not to exceed substantially the speed of starting.

It is the object of our invention to provide a method and apparatus and controls for practicing the method of rolling metal sheetsl and the like'` at speeds as high as 10,0 per lcent greater than the initial starting speed.

It is the object of this invention to provide the step of moving metal between rolls at such speed as to overcome the inertia of the mass of metal without rupturing the metal sheet; the step of increasing gradually the speed ofthe metal sheet and the rolls when this initial inertia has been overcome, and of increasing the speed at such a rate that the sheet is constantly accelerated but never to a point where it is ruptured as the increase is just under that speed which would bring about a rupture.

It is a further step in the method that after bringing up the speed gradually by gradual increments, to then maintain that speed, all without any control, withoutk utilizing the sheet for control purposes. It is anobject of this invention to eliminate sheet control without utilizing the sheet itself for that purpose.

It is an object of this invention to provide a speed control apparatus and control circuits for controlling the action of rolls rolling metal sheets where the inertia of the metal is such that if the initial speed of the rolls exceeds a predetermined point, the metal sheet being rolled will be ruptured. It is further necessary to accomplish as great a speed as possible, both for productive reasons and for the purpose of giving a suitable l burnished surface to the metal sheets being rolled.

A particular object of this invention is to provide a variable speed power transmission con- 1937, SerialNo. 158,364 (Cl. -32) nected to driving rolls for metal sheet rolling and means of adjusting the speed of this transmission so that it will not exceed a predetermined low speed or high speed; and so that between the minimum and maximum speeds it may be set to run at predetermined intermediate high and low speeds. The advantage of this arrangement in rolling of metal sheets and the like is that the rolls can be started for the initial rolling action until the inertia of the metal is overcome and 10 they can be ther. increased in their speed gradually up to predetermined limits. so that the speed of the rolls is never greater than that which the strength of `the metal will stand without rupture. 15

It vis an object of this invention to provide power driven rolls with a variable speed transmission interposed between the prime mover and the rolls capable of an innite number of speeds with a pilot motor adapted to adjust the variable speed mechanism, and with a suitable electrical control for said pilot motor which can be operated to bring the adjustment of the variable speed transmission to a predetermined point, at which point a control switch renders the pilot 25 motor inoperative and the transmission continues to operate at the predetermined speed thus set.

It is a further object in this connection to provide means for temporarily manually controlling the intermediate movements of the pilot motor or of setting the electrical mechanism for operating the pilot motor to bring about a predetermined speed without further manual attention.

Referring to the drawings: 30

Figure 1 is a diagrammatic view showing the mechanical and electrical arrangements comprising this invention.

Figure 2 is a side elevation of the supply takeup and rolling rolls for the metal sheet and the variable speed transmission with the driving motor.

Figure 3 is a top plan View of the variable speed mechanism.

Figure 4 is a section on the line -fi of Figure 1 showing the adjustable nature of the controlling lever operating the control speed setting switch.

Referring to thel drawings in detail, a main 50 driving motor I is connected to the incoming power lines 2, 3 and :i through the main switch 5. This motor drives through the belt 6, the pulley 'l on the driving shaft il of a variable speed transmission generally designated 9. v5.5

Mounted on this shaft are a pair of discs l0 which can be moved inwardly and outwardly by the arms il in the usual manner tovary the speed of the driven shaft l2. These arms are pivoted at i3. At their other ends they are connected to the driven discs l which are simultaneously moved inwardly and outwardly oppositely to the movement of the discs it.

Between these discs is a power transmitting belt l5. The arms il are actuated inwardly and outwardly by the screw t which is threaded through blocks l1 and iii on the ends of the levers Il. This screw is rotated in opposite directions through the gear box i9 by the pilot motor 2Q.

The driven shaft l2 is connected by either gears or a chain to the rolls to be driven. In this instance is shown a chain 2l' mounted on suitable sprockets 22 and 23 for driving the roll 2li. superimposed above this roll is another roll 25. These rolls are interconnected by gears 26 and 21. v The metal sheet 28 passes between the rolls, as indicated by the arrows.

Returning to the variable speed transmission, it will be observed that there is mounted on one side thereof a switch arm 29 that has a roller 3Q on one end thereof. This switch arm is adapted to open and close the contacts 3i and 32. It is actuated by the adjustable control lever which is guided at one end by the slotted bracket Sti and which is connected at the other end 35i by the bar 31 to the lever i i. rThe bar 31 has graduations 3S, and superimposed upon this bar is the lever 33 which has a slot 39 through which project the set screws lli for adjusting the overall distance between support 35 and the end oi the lever. This lever is provided with a cam shaped recess tl, the outer end oi which engages the roller` 3@ to open and close the switch. rThis switch is adapted to control the operation, under certain conditions, of the pilot motor 25B as hereinafter described.

There is also associated with this transmission a low and high speed limit switch which completely stops the actuation of the pilot motor if the speed decreases below a predetermined point or increases above a predetermined point; This is effected by the low speed switch lever 42 being engaged by the end of the lever il opening the switch @53. Likewise the high speed lever @il controlling the switch 45 may be similarly actuated.

Electrical control mechanism The purpose of this electrical control mechanism is to close an electrical circuit to actuate the pilot motor 2i? so that it will continue to operate in either direction selected `to bring the transmission gradually to a predetermined setting for high or low speed. A part of this circuit is arranged so that by merely holding in the so-called slow or fast buttons on the switchboard, the pilot motor will continue to operate as long as these buttons are held in, limited by the action of the limit switches l2 and M.

There are other buttons which likewise control the mechanism but only have to be pressed into closing position and then can be released as the electrical setting mechanism and holding mechanism will continue to function automatically thereafter. This latter arrangement operates as follows.

Automatic high speed The automatic high speed button i6 is pushed in toengage the terminals 41 and 48. In doing so it closes the following circuit. The Wire 49 is connected to the solenoid 5B of the fast holddown 5| which is thus closed. The wire 52 leads to the terminal 32 of the control speed setting switch 29. The other side of this switch at 3l is connected by the wire 53 to the high speed solenoid switch 5G which closes the switch 55. This results in bringing the three-phase lines 56, 51 and 53 of the pilot motor 2F) in circuit in such a marmer that the motor 2B will move the levers Il together in such a manner as to move the discs lil together, thereby increasing the speed of the rolls.

This will continue until the switch points Si and 32 are opened by the control lever 33 engaging the roller 3U, moving the lever 2Q to open the circuit. Thereupon, the rolls having been brought up .to the predetermined high speed, according to the adjustment of the lever 33, will continue to operate at that speed. The lines 59, 60 and 6| are also in circuit so that if the speed should exceed a predetermined amount, the high speed switch lever lill would be actuated and the pilot motor stopped. The same is true of the operation of the low speed lever d2.

There are also brought in circuit the wires E2 and 63 which include a signal light Btl that is illuminated when the machine is: ruiming at high speed. It. it is desired to stop the pilot motor for any reason, the push button 65 which is normally closed across the terminals 66 and '51 may be operated to open the circuit and stop the pilot motor at any time.

Slow speed automatic control The slow speed button 68 operates in a similar manner in that it brings in circuit, by bridging theterminals 69 and 1i), the slow hold-down solenoid 1l of the slow hold-down switch 12 through the wire 13. It also brings in circuit the slow speed switch solenoid 1li ,for operating switch 15 which reverses the direction of the pilot motor 20 and causes it to operate in the reverse direction to that just indicated. The speed will be brought down gradually to the predetermined low speed, at which point the control lever 42 will operate and render the pilot motor inoperative and the machine will continue to run at the predetermined low speed.

The manual hold-down slow speed button 11 is adapted to operate, as indicated, the slow speed switch solenoid 1li and switch 15 without bringing in circuit the hold-down switch and its solenoid 1| and switch 12. When this button is released manually, then the pilot motor is no longer actuated. Likewise the fast hold-down button 16 only closes the circuit through the fast hold-down solenoid 54 and switch 55 and does not involve the fast hold-down switch solenoid 5U and the switch 5|.

This electrical control therefore consists of the following: a pilot motor that can be operated in either direction for setting the variable speed transmission to a predetermined high or low speed. When once started by the high speed or low speed switch, or operated with the hold-down switch if that is used, the pilot motor will continue to operate in the direction in which it is set to move until itis stopped by the movement of the transmission being so adjusted to the pilot motor which opens the switch 28, 132 or M. It will continue to operate at the speed so set. It is apparent that any number of such adjustments may be eiiected'as desired andthat only one typical form has been indicated here.

One of the particular advantages of this invention is that the control does not depend upon any contact with the sheet being treated.

Another important advantage is thatthe rolls,

may be brought up to speed and the sheet being treated brought up to speed to overcome the inertia of the latter and to bring both the rolls and the sheet into a harmonious speed relationship at slow speed; that thereafter when the pilot motor is put into operation, the transmission is gradually increased in its speed relationships so that the rolls are gradually speeded up without rupturing the sheet being handled and by this: gradual means the sheet can be handled at much higher speeds than heretofore thought possible, and with improved results of finish, etc. The maximum speed can be set according to the setting of the control lever as the graduations 38 indicate in terms of speed setting desired. The control lever then stops further adjusting the movement of the transmission by opening the pilot motor circuit and themachine will operate at the speed to which it has thus been brought up gradually. Likewise it can be controlled by varying the speed by using the fast and slow push buttons. Intermediate positions can be accomplished by holding in the fast or slow switch buttons 'i6 or l1 so the exact speed of the adjustment is always within the control of the operator, thus limiting the effect of shutdowns and the like.

It has been found possible With this invention One `of the typical uses of this invention is in connection with metal rolling such as the production and thickness of metal sheets, the surfaces of which must be burnished in order to make them into foil. The sheet 28 is fed from a supply roll 28a and is taken up on the take-up roll 28h. The inertia of this sheet and its associated supply roll must be overcome in starting without rupturing the sheet. The rolls are therefore started up at a predetermined relatively low speed which is insufficient to rupture the sheet but which will gradually overcome the inertia of its mass so that it will satisfactorily pass between the rolls. Heretofore this has been thought to be the maximum speed of which the sheet would be capable without injury. It was also thought that the rolls would not suitably burnish the sheets and that the bearings of the rolls would not stand higher speeds in view of the pressures employed.' These speeds were about feet per minute. However,

by this invention it is possible to increase these speeds up to 300 feet per minute and the total possible maximum speed has not yet been completely explored, as these `speeds are constantly being increased by the use of this invention.

By this invention, after this initial speed has been raccomplished by the original setting of the speed transmission, the speed is gradually increased by adjusting the transmission through the pilot motor 20. This speed progressively increases the speed of the sheet as the speed of the rolls is increased. This continues until the maximum speed selected has been accomplished when the pilot motor is rendered inoperative. The speed is increased gradually always beneath the rupturingl speed for the metal, but progressively accelerating `the sheet and the rolls.

It vhas been found that thishigher speed of the rolls gives a much more superior burnishing action onV the sheet so that there is an improved product, and the bearings of the rolls, `due to the higher speeds, experienced improved lubrication `and operation instead of the reverse which was expected. l

It has been found possible, therefore, to roll extremely delicate and thin sheets of metal from heavier sheets at these high speeds, thus increasing production proportionately without injury to the metal and with the minimum of shut-downs due to the rupturing of the sheet.

The method of doing this comprises the step of moving the metal between the rolls at such a speed to overcome the inertia of the metal without rupturing the metal sheet and the further step of increasing the speed of the metal sheet and the rolls when this inertia has been overcome, at such a rate that the sheet is never ruptured but the speed of the sheet is increased up to, but just under, that speed which would bring about a rupture. This requires the automatic control features of this invention.

The claiming of the apparatus for variable speed control of rolls operating upon a sheet and similar mechanism is covered by a copending application, Serial No. 158,363 filed August `10, 1937.

It willbe understood that We desire to comprehend within our invention such modifications as come within the scope of the claim and the invention.

Having thus fully described our invention, what f we claim as new and desire to secure by Letters Patent, is:

In a method of processing strip or sheet metal.`

at a speed just below the point at which said sheet will rupture.

DARCY E. LEWELLEN.

EMIVIONS F. LEWELLEN. 

